Still SO confused which rail type

For this small number of journeys I would suggest buying point-to-point tickets in advance. London to Canterbury will have relatively little discount for advance purchase and I would suggest buying the ticket on the day, especially if you are flying into London and going to Canterbury on the same day. Advance-purchase tickets are generally limited to single trains and if you miss them (unless it's due to a delay on an earlier train) you have to buy a new full-fare ticket. However, I would suggest buying your other two trips within the UK in advance. I would suggest getting both from First Great Western at www.firstgreatwestern.co.uk.

For both of your German journeys, you should book in advance at www.bahn.com. The exception would be if you are flying into Nuremberg and leaving for Quedlinburg the same day, as if your flight is delayed you would have to buy a new full-price ticket.

I am not sure what the confusion. Buying ticket is just like buying an airplane ticket. If you want to go from A to D just log onto the rail site and plug in A to D. Sometimes it could be directly or you will have to change trains just like changing airplanes if you do not have a direct flight. A point-to-point ticket is just that - from point A to point D. You beginning and ending point of your journey.

Be you understand all the ins and outs of the Ryanair. Their great fares evaporate quickly with extra fees. They made most of their money from charging extra fees so follow their rules very carefully or it will get expensive quickly. Don't even think of fudging anything with Ryanair.

You don't mention the timing of this. There are full fare options from Nuremberg to Quedlinburg of 83 euro.
If you opt for one night in Nuremberg first, you could book an advance purchase nonrefundable ticket for as low as 29 euro. For the leg to Frankfurt airport, you can get advance purchase nonrefundable tickets for as low as 29 euro if you go out 90 days. It will be more if the trip is near term. The full fare with only 2 changes is 109 euro.

Thank you all.

You mentioned knowing my times would help you assist me. My itinerary is as follows:
2 September - arrive at Heathrow. Travel to Canterbury from the airport. Stay 3 nights.
5 September - leave Canterbury and travel to Abergavenny. Stay 2 nights
7 September - leave Abergavenny and travel to Stansted Airport. Fly from Stansted to Nurnberg. Stay 4 nights.
11 September - leave Nurnburg and travel to Quedlinburg. Stay 3 nights.
14 September - leave Quedlinburg and travel to Frankfurt Airport. Fly home :(

I have decided to take the coach from Heathrow to Canterbury. I'll have to take rail from Canterbury to Abergavenny , and then Abergavenny to Stansted for time's sake.

My new question is, what are the best booking site/rail lines/travel tips for those two rail journeys?

Also, I have decided to use the Deutsche bahn rail system for my 2 journeys in Germany. Same question: Any insider tips for best booking/rail/etc.?

All assistance is much obliged!

I am not too expert in UK train tickets, but http://www.nationalrail.co.uk/ is a start. that should direct you to the correct private carrier for your individual train trips in the UK.

www.bahn.com is the place to get Deutsche Bahn tickets. Since you will be in Nuremberg for a few days, you can buy Sparpreis tickets, which are train specific nonrefundable tickets for big discounts over standard rates.

Since you will be in Nuremberg for a few day,
http://www.vgn.de/CFF6B06F-C0B4-11D7-AE44-00034709FE0C
This site will give you prices for local transit and day passes in the Nuremberg area.

The Savings Fare tickets can be a good deal IF you can commit to a specific train (date and time). It looks like you should be able to.

Prices for the tickets start at 29€ 92 days before the travel date and go up as the lower priced ticket sell out (unlike airplanes, they never go down). Your probably too late to get the best farew. For your trips to Quedlinburg and Frankfurt, I can still see a few trains with 39€ tickets available, but you need to purchase them online, from the German Rail website, soon. German Rail will email you a pdf file from which to print your ticket.

If you can't get he 39€ price, you can get a Quer-durchs-Land-Ticket, for 44€ for one person, anytime. You can purchase it at the station from an automat the day you leave for the same price. It will cover you after 9 AM for unlimited travel on regional trains all over Germany that day.

Canterbury->Abergavenny. Route Canterbury West-London St Pancras-London Paddington-Newport-Abergavenny. Cost: £80. Valid mornings and after 17:00.

Abergavenny->Stansted. Route Abergavenny-Newport-London Paddington-London Liverpool Street-Stansted Airport. Cost £75. Valid to arrive at Stansted after around 14:30. If you need to get there earlier it will cost £95 or £115.50 for the earliest arrival at 11:44.

Both routes involve 3 changes, plus a cross London underground journey.

Wow, thanks everyone!

I found a first class rail ticket from Nurmberg to Quedlinburg for 39 Euros! (only 8.00 more than second class, so I figured what the heck - go for it!) And one from Quedlinberg to Frankfurt as well.

Thank you Sam for the day pass info. :)

So I'm down to just the UK transportation now. Marco, thank you for listing the specific stops. I understand Britain has privatized railways, and most routes can be operated by several companies. Any suggestions who to book with? via which site?